Environmental Information Exchange

Energy Efficient IT Systems

In 40 years the computer has moved from a research tool to a common item used by nearly 1 billion people.  The evolution of computer technology to IT devices (information technology) within businesses continues to increase.  All computers use energy and are meant to be tools of efficiency, however there is a range of ways IT systems can be energy efficient in the workplace. 

Desktop computers

PCs (personal computers) or desktop computers are designed as stationary devices.  In the workplace they are mainly connected to networks and are sometimes used all day by staff.  They are often at 500 to 600 Watts but often average much less than this during normal use (60-100 Watts).  Newer computers may use even less energy.

PCs are often switch on and off manually.  Most PCs are set to reduce power consumption after a period of non-use, however this may reduce consumption to 20-50 Watts.  Further, networking software may be set to automatically switch off the computer at a particular time.  Ideally PCs set to be completely off when not in use can save energy, particularly in workplaces where there may be hundreds of computers.

Laptop computers

A laptop is a portable IT device that runs off a battery or a charger.  Laptops tend to use 20-60 Watts.  Most laptop chargers continue to consume a small amount of power (3 to 7 Watts) even when the battery is fully charged.

Like desktop computer, laptops are switched on and off manually.  They all have energy conservation settings for periods of non-use.  Because laptops may not be linked to part of a network, they may not be automatically shut down.  Ideally laptops will be completely off when not in use and chargers will also be off when charging is complete.

IT Servers

Servers are computers mainly used for providing email and website services as well as some network functions and storage.  As a result these need to be on constantly to meet demand; like a PC energy consumption varies based on demand.  Some organisations may require a small server to meet their needs, though many organisations have a number of servers in a dedicated server room.  A number of machines in a small space generate heat, increasing the potential risk of device failure due to overheating.  Some IT server rooms are air-conditioned to reduce this risk.

Servers are on constantly, and are only switched off when being replaced.  Ideally energy reduction is achieved by rationalising all servers, switching off unneeded equipment.  Awareness of optimal operating temperatures and use of natural ventilation will reduce demand for air-conditioning.

Wireless routers

Increasingly these devices are used to provide computers with a wireless means of accessing the internet.  They usually consist of a modem and means or broadcasting a signal and are often supplied by an internet provider.  Wireless routers use 20-60 Watts depending on the strength of signal.

Wireless routers are controlled manually but are often left on in practice.  Ideally wireless routers will be completely off when not in use, though some manufacturers recommend against this.

Printers, display screens, and peripherals

Computer and IT equipment are connected (either directly or via networks) to a range of input / output devices that use energy.  These include printers, display screens, and other peripherals such as scanner and plotters.  These devices use energy, even when idle.  A typical printer uses 20-50 Watts, though larger devices can use hundreds of Watts.

Printers and other peripherals have manual controls but are often left on.  Some network software can automatically switch these off.  Further some plug socket devices exist that will switch off peripherals when computers are switched off.  Ideally printers, display screens, and other peripherals will be completely off when not in use.